Epitaxial growth mechanism of high-crystallinity lanthanum hexaboride (001) thin films on silicon (001) by electron beam deposition

摘要

The growth of high-quality LaB6 thin films on Si(001), by using electron beam deposition, is reported. The films show (001) orientation as confirmed with X-ray diffraction and electron backscattered diffraction (EBSD). The sharp Kikuchi pattern from EBSD evidences a single-crystalline nature of the LaB6(001) films. To accommodate for the lattice mismatch, the LaB6 is azimuthally rotated by 45 degrees with respect to the Si lattice (LaB6[100] divide divide Si[110]) and grows in a supercell structure. Early stages of the film growth were clarified using atomic force microscopy, with a unique "directional" and "island-to layer-by-layer" type of growth of this covalently bonded heterosystem.